If you wanted to estimate a population mean where you know the standard deviation of the population is 152,

what is the smallest sample size you can have in order to get a margin of error less than 4 for a confidence level of 90%? (Remember n needs to be an integer).

so I know the formula for margin of error is
Z*std.dev/square root of n so
1.645*152/square root of n

Is there a way to find n?
I keep plugging in random numbers for n to see if I get any integer less than 4
but I can't seem to get any integer less than 4?
Is there a different way to doing this problem please help!

the inequality is 1.645*152/sqrt(n) < 4
sqrt(n) > 1.645*152/4

n > (1.645*152/4)^2 > 3907.5
= 3908
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